John, to be quite honest, I haven't had derailments since I changed to Walthers/Shinohara turnouts. I used Atlas, for economy, but had problems. I made the change and now, no problems. I also weight my cars to NMRA Best Practices.
About 20%, as I recall. Shinohara makes the switches for Walthers. Shinohara is more expensive than Walther or Atlas. Atlas had a quality problem when I did my layout. Our club used Walthers and had no problems with cars jumping the rail. The biggest reason I switched to them. I was having to file the frogs to open them up with Atlas. Not fun.
I have heard that the problems have been addressed by Atlas, and corrections made. But, too late now. And I have no evidence to substatiate that claim.
Buy a couple different turnouts from various companies. Make a test track or three. Take what you consider your best piece of rolling stock from a performance perspective and run it slowly over the test tracks. Then take your WORST performer and see what happens.
yeh, stumbled across interesting issue with my crossover between loops. one of the cars derails immediately upon getting on thrown switch. slow or fast. i have to exact cars in diff road name. one derails, one not, no matter where are they located in the train. i read the thread about things obstructing bogey motion, looked over and found nothing. cars look identical to me... for now i'm ready to chalk it up to peculiarities of atlas switches but i will look more carefully at it today. will need to look into better switches but i actually don't lke that crossover that much anyways...
I have a friend that uses Peco switches and loves them. I don't have much, if any, experience with them. The N-Scalers at the old club used them, though. But, as we all know, the difference in scales is like night and day.